Innate immunology Flashcards
What type of cells does innate immunity involve
Macrophages NK cells Neutrophil Eosinophil Basophils Dendritic cell T cell and natural killer t cell
Innate immunity
Non-specific, first line of defence
Comes into play within hours of antigen appearance
What mechanism does innate immunity include
Physical barriers like skin
Chemicals in blood
Immune system cells that attack foreign cells in body
Two types of phagocytes
Macrophages- reside in tissue and recruit neutrophils
Neutrophils- enter infected tissues in large numbers
Two types of phagocytes
Macrophages- reside in tissues and recruit neutrophils
Neutrophils- enter infected tissues in large numbers
What is Phagocytosis
Capture, engulfment and breakdown of bacterial pathogens
What is needed to initiate specific adaptive immune response
Innate immune response
What is toll like receptor
Mammalian pattern recognition receptors abundant on macrophages, neutrophils and the epithelial cell of the gut
What type of receptors are TLRs
Type I transmembrane receptors
Which TLR recognises bacterial lipids
TLR 1,2,4 and 6
Which TLR recognises viral RNA
TLR 3,7 and 8
Which TLR recognises bacterial DNA
TLR 9
Which TLR recognises bacterial or parasitic proteins
TLR 5 and 10
Two granular leukocytes
Basophils and eosinophils
What do neutrophils do
Secrete cytokine# to attract other immune cells
Release lysosomal enzymes that are responsible for inflammation and tissue damage
What do macrophages do
Engulf damaged tissue or microbes
What do monocytes do
Engulf ,icorbes and differentiate into macrophages and dendritic cells
What do Dendritic cells do
Process and present antigen-so they can be recognised by other lymphatic cells
What do basophils do
Release chemicals that produce inflammatory responses
What do eosinophils do
Enter infected tissue and produce enzyme which breakdown chemicals released by basophils reducing inflammation
What do NK cells do
Activated by interferons or cytokines to destroy infected cells with a wide range of viruses and cancers
What cell surface receptors do macrophages and neutrophils have
Pattern recognition receptors like TLRs
Receptors for Fc portion of antibodies as well as C3b component of complement
What does ligand binding to receptor on phagocytes do
Causes actin polymerisation at site of pathogen attachment, causing plasma membrane to surround the pathogen and engulf it in phagosome
What happened of pathogen is too large to engulf
Group of macrophages, neutrophils and eosinophils gather around pathogen
Secrete their defensins and other lysosomal products by exocytosis
Three acute phase proteins
Mannose-binding lectin
C-reactive protein
Complement
What does MBL do
Binds to bacterial surface with particular spatial arrangement of mannose or fucose
What does C-Reactive Protein do
Binds to phosphorylcholine on bacterial surface
What does complement do
Set of proteins which bind to bacterial surface
What are acute phase proteins
Set of plasma proteins whose level increases during infection to enhance host defence mechanisms
What stimulates fever
Pyrogens
What does increase in body temperature do
Stimulate WBC to deploy and destroy microbes
Increase in immunological response
Slow down growth of or kill pathogen
What are the four cardinal sign of inflammation
Redness
Heat
Swelling
Pain
Primary functions of inflammation
Localise infection
Neutralise toxins at injury site
Repair tissue damage
Major events of inflammation
Vasodilation
Increase in permeability of capillaries
Mobilisation of leukocytes to site of injury
Phagocytosis
3 complement pathways
Classical pathway
Mannan-binding lectin pathway
Alternative pathway
Immunological function of C3a
Mast cell degranulation
Target- mast cell
Immunological effect of C3b
Opsonisation
Target- pathogen surface
Immune complex clearance
Target- red blood cell
Immunological effect of C3d
Mast cell degranulation
Target- mast cell
B-cell activation
Target- B cell
Immunological effects of C4a
Mast cell degranulation
Target- mast cell
Immunological effects C4b
Opsonisation
Target- pathogen surface
C5a immunological effects
Mast cell degranulation
Target- mast cell
C5-C9 immunological effects
Cell lysis
Target- infected cell
